1.0. Field of the Invention
This invention relates generally to pipe sealing devices, and more particularly to such devices including heat activated sealing mechanisms for sealing the gap between a pipe and its passage through a wall.
2.0 Discussion of Related Art
A pipe seal of the type in question is used to protect openings or channels in walls or ceilings where pipes pass through. The pipes are generally made of thermoplastics, more particularly polyvinyl chloride, polyethylene and polypropylene, and are generally circular in cross-section, pipes with external diameters of 32 to 400 mm mainly being used in the construction industry.
A pipe seal with very good fire-proof properties is described in applicants' DE 39 30 722 A1. However, it is inconvenient for some applications and entails preassembly of its components in accordance with the particular pipe diameter.
EP 0 486 299 A1 describes a bendable sheet-metal sleeve or a sheet-metal casing provided on its inside with a layer of mouldable swelling compound. In addition, a strip of plastic swelling compound may be associated with this layer to ensure that the metal casing with the swelling compound fits tightly around the pipe.
In a known modification of this construction, the inside of the metal casing is coated solely with a viscous paste of swelling compound.
Finally, it is known that pipes or cables in wall channels can be wrapped in endless tapes of narrow strips of solid swelling compound based on waterglass which are welded between two films and which can be wrapped around the pipes or cables to be protected in one or more laps. The laps are held together by the brickwork surrounding them.